Question about Amplifiers & Preamps

1 Answer

My old Marantz Amp isn't well...

I have an old Marantz Amplifier ST353 has suddenly developed a problem where the output side of the unit is effectively non existent. I can have the whole unit connected as per normal but in order to get any sound out of it at all, I have to have the volume cranked to maximum and even then, I can only just hear it with head right next to speaker. Could this be power supply problem to amp fets or something more sinister? Rest of unit functions as per normal. Any help would be greatly appreciated as when working, is a ripper little unit.

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 7 Answers
Re: My old Marantz Amp isn't well...

If there are any, make sure you have the set of speakers configured correctly on the amp. There maybe a set of buttons for example button A is for one set of speakers and button B is for the other, make sure this is all configured correctly

Posted on Jan 05, 2008

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

3 Answers

I have a Marantz turntable, a Marantz CD player, an Eltax tape player and a Marantz amplifier with two Cambridge speakers, how do I assemble them into a stack system please ? Thank you

All the sources, turntable, CD player and tape unit have an output. These should go in the input of the amplifier with the same name. Then only the Tape player, could have an input, for recording music or whatever. For that input, your amplifier should have an tape out. All these should be connected with cables with tulip plugs, like these.

Use the white for left on everything and red for right.
If one of the devices as a different connector, find a cable for audio, with on one end the tulip plugs and on the other end the fitting plug.
Then the output of the power amplifier it should say output or LS, can be connected with 2 wires going to the speakers.
For this the same counts, although it is difficult to see when you use electrical wires in one colour. What comes out red on he amp, should go on the same screw connector on the speaker. Just to avoid one speaker being out of phase. It will work, but could sound a little strange when the speakers are out of phase.
With the correct model names added, perhaps we could have given a more accurate answer.

Please don't test the system or switch on, with the volume button to the max. Don't switch anything on an amplifier when the volume is high, or the setting is high. A short increase of the volume, during switching can, and has very often destroy(ed) the speakers.

Mar 11, 2015 | Marantz Amplifiers & Preamps

1 Answer

How do I check the internal wiring for input voltage on a Marantz 4060 Quad Amp?

The only way would be a voltage selection switch on the back of the unit, or changing pigtail leads on the primary side of the power transformer.

Apr 30, 2014 | Marantz MA-9S1 2-Channel Amplifier

1 Answer

I have a Sherwood Nottingham R-925RDS receiver. No matter what input I select it does not connect to the amplifier section. Everything else appears to function ok. Unit switches on & off, correct...

Let's work with FM as that is ONboard and can't be connected wrong. Does THAT work?

Turn the volume control to something medium.

The errant switch, control or condition may change and you will suddenly release the amp's full power and possibly destroying your speakers. If a signal isn't audible at 1/2 volume it's probably not there.

Carefully examine the front panel for clues like a misplaced Mute or Tape Monitor control or Multichannel Analog Input selected.

There is a good chance that a common control may have developed a high-resistance or 'dead' spot through idleness and is causing your symptom. Turn the POWER OFF and operate every control throughout its range a number of times, especially rarely-used ones like Tape Monitors and the Mute control.

Turn the volume to something reasonable and see if that helped.

May 06, 2011 | Sherwood Amplifiers & Preamps

1 Answer

Hello i have a marantz pm-47 amp that keeps blowing every time i plug in the power feed to the amp board i have changed the 2 caps on the board but still have the same problem i checked voltage for...

Hi mas_66,
Make sure that the fuse is the same rating with the old one.
If still symptom persist, I've suspected that your output IC is shorted.
You may hang this IC, then power up the unit.
Observe what will happen, if this cure the symptom then this is a clear indication that this IC is shorted and made the fuse blown while it is in the circuit board.
Hope I helped you.
Have a nice day!
Thanks for using Fixya.

Mar 08, 2011 | Marantz PM-68 Amplifier

2 Answers

Marantz dedicated amplifier squeals

The symptom sounds like a feeback loop. As long as that indicator is showing near maximum output on one channel AVOID ATTACHING ANY SPEAKERS TO IT!!!! You'll cook the tweeters.

Turn it off and manually operate every control, knob and pushbutton throughout its range many times to wipe oxides away from their conductors.

Set all EQ controls to their midpoints and re-evaluate.

We don't know if it's an input or output problem yet. Does it do that with all inputs?

Jan 19, 2010 | Marantz PM7200 2-Channel Amplifier

1 Answer

Can I remotely control speaker outputs on the Marantz PM 8003?

You need an 8 ohm stereo "L-pad"

Dec 21, 2008 | Marantz Amplifiers & Preamps

1 Answer

Marantz PM-34 Problem

Hi there

The part that you speak of is called the emitter stabilizer resistor. It is common to the output pair on one channel. You will find that the large "output" transistors mounted to the heat sink either side of this resistor will most probably be faulty.

Best not to run the amp at all whilst in this condition.

To be sure that you have an effective repair, you will need to change both these parts, and also the "driver" transistors that connect to the outputs. They too are in symmetrical positions close to the the output transistors. You should also check that the 3 legged resistor you mentioned is measuring its correct value, and check all other low value resistors in the output stage area to that channel.

If you are not familiar with repairing this sort of equipment, perhaps you can find a repair guy with some experience on audio equipment, then this work should be all he needs to do to repair the amp. I would also ask him to "blanket resolder" the output/bias stages and power regulator stages in the amp as problems with heat stressed cracked/failed soldering and dry joints often cause these amps to blow the output transistors.

BE SURE THAT THE CORRECT PARTS ONLY are used for the repairs. Different transistors could cause future problems with the amp. The parts can be obtained relatively easily from a marantz distributor(we can find one in a country near to you). OR if you can give me the markings to each of the parts you need, I can provide you with an international source to get them from.

The amp is decent HiFi, and worth repair. Happy to provide you any assitance I can, Good Luck


Nov 02, 2008 | Carver PM950 Amplifier

1 Answer

Marantz PM-48 connecting to TV

look on the back of the TV and there should be L/R audio outputs (white & red), connect this to a spare input of your amp via a connecting lead eg. AUX or any other input except PHONO.

hope this helps.

Oct 19, 2008 | Marantz PM-68 Amplifier

1 Answer

Marantz curiosity question

Hi spanky

The pre power combination would be the preffered rig. Has better power output, and more bang for your buck visually with the extra amp to the rack. The meters look great too. If you can go for them, then, do it. I would :) Just let me know which unit you would like to run up and I will photoshop up a rear view to show you how to connect it together. .


Jul 21, 2008 | Amplifiers & Preamps

1 Answer

Marantz PM7200

no! you got shorted or leak capacitors, and change value resistors.

Sep 23, 2007 | Marantz PM7200 2-Channel Amplifier

Not finding what you are looking for?
Amplifiers & Preamps Logo

Related Topics:

65 people viewed this question

Ask a Question

Usually answered in minutes!

Top Amplifiers & Preamps Experts


Level 3 Expert

4518 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17129 Answers

The Knight
The Knight

Level 3 Expert

66444 Answers

Are you an Amplifier and Preamp Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides